iterate throug points form a geoJson?

Hello again..
I cant find how to now the number of ie: points there are stored in a datasource when read from a geoJson file, so I canie: iterarte and label them....
How can I access this property?
Thank you

After loading GeoJSON into a GeoJsonDataSource, you can get the data source’s DynamicObjectCollection, and from there you can access each of the individual DynamicObjects:

var dataSource = new Cesium.GeoJsonDataSource();

dataSource.loadUrl(’/Nevada.geojson’).then(function() {


var dynamicObjectCollection = dataSource.getDynamicObjectCollection();

var objects = dynamicObjectCollection.getObjects();

for (var i = 0; i < objects.length; ++i) {